audk/ShellPkg/Include/Library/FileHandleLib.h

396 lines
15 KiB
C

/** @file
Provides interface to EFI_FILE_HANDLE functionality.
Copyright (c) 2009, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
/**
This function will retrieve the information about the file for the handle
specified and store it in allocated pool memory.
This function allocates a buffer to store the file's information. It is the
caller's responsibility to free the buffer
@param FileHandle The file handle of the file for which information is
being requested.
@retval NULL information could not be retrieved.
@return the information about the file
**/
EFI_FILE_INFO*
EFIAPI
FileHandleGetInfo (
IN EFI_FILE_HANDLE FileHandle
);
/**
This function will set the information about the file for the opened handle
specified.
@param FileHandle The file handle of the file for which information
is being set
@param FileInfo The infotmation to set.
@retval EFI_SUCCESS The information was set.
@retval EFI_UNSUPPORTED The InformationType is not known.
@retval EFI_NO_MEDIA The device has no medium.
@retval EFI_DEVICE_ERROR The device reported an error.
@retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
@retval EFI_WRITE_PROTECTED The file or medium is write protected.
@retval EFI_ACCESS_DENIED The file was opened read only.
@retval EFI_VOLUME_FULL The volume is full.
**/
EFI_STATUS
EFIAPI
FileHandleSetInfo (
IN EFI_FILE_HANDLE FileHandle,
IN CONST EFI_FILE_INFO *FileInfo
);
/**
This function reads information from an opened file.
If FileHandle is not a directory, the function reads the requested number of
bytes from the file at the file's current position and returns them in Buffer.
If the read goes beyond the end of the file, the read length is truncated to the
end of the file. The file's current position is increased by the number of bytes
returned. If FileHandle is a directory, the function reads the directory entry
at the file's current position and returns the entry in Buffer. If the Buffer
is not large enough to hold the current directory entry, then
EFI_BUFFER_TOO_SMALL is returned and the current file position is not updated.
BufferSize is set to be the size of the buffer needed to read the entry. On
success, the current position is updated to the next directory entry. If there
are no more directory entries, the read returns a zero-length buffer.
EFI_FILE_INFO is the structure returned as the directory entry.
@param FileHandle the opened file handle
@param BufferSize on input the size of buffer in bytes. on return
the number of bytes written.
@param Buffer the buffer to put read data into.
@retval EFI_SUCCESS Data was read.
@retval EFI_NO_MEDIA The device has no media.
@retval EFI_DEVICE_ERROR The device reported an error.
@retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
@retval EFI_BUFFER_TO_SMALL Buffer is too small. ReadSize contains required
size.
**/
EFI_STATUS
EFIAPI
FileHandleRead(
IN EFI_FILE_HANDLE FileHandle,
IN OUT UINTN *BufferSize,
OUT VOID *Buffer
);
/**
Write data to a file.
This function writes the specified number of bytes to the file at the current
file position. The current file position is advanced the actual number of bytes
written, which is returned in BufferSize. Partial writes only occur when there
has been a data error during the write attempt (such as "volume space full").
The file is automatically grown to hold the data if required. Direct writes to
opened directories are not supported.
@param FileHandle The opened file for writing
@param BufferSize on input the number of bytes in Buffer. On output
the number of bytes written.
@param Buffer the buffer containing data to write is stored.
@retval EFI_SUCCESS Data was written.
@retval EFI_UNSUPPORTED Writes to an open directory are not supported.
@retval EFI_NO_MEDIA The device has no media.
@retval EFI_DEVICE_ERROR The device reported an error.
@retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
@retval EFI_WRITE_PROTECTED The device is write-protected.
@retval EFI_ACCESS_DENIED The file was open for read only.
@retval EFI_VOLUME_FULL The volume is full.
**/
EFI_STATUS
EFIAPI
FileHandleWrite(
IN EFI_FILE_HANDLE FileHandle,
IN OUT UINTN *BufferSize,
IN VOID *Buffer
);
/**
Close an open file handle.
This function closes a specified file handle. All "dirty" cached file data is
flushed to the device, and the file is closed. In all cases the handle is
closed.
@param FileHandle the file handle to close.
@retval EFI_SUCCESS the file handle was closed sucessfully.
**/
EFI_STATUS
EFIAPI
FileHandleClose (
IN EFI_FILE_HANDLE FileHandle
);
/**
Delete a file and close the handle
This function closes and deletes a file. In all cases the file handle is closed.
If the file cannot be deleted, the warning code EFI_WARN_DELETE_FAILURE is
returned, but the handle is still closed.
@param FileHandle the file handle to delete
@retval EFI_SUCCESS the file was closed sucessfully
@retval EFI_WARN_DELETE_FAILURE the handle was closed, but the file was not
deleted
@retval INVALID_PARAMETER One of the parameters has an invalid value.
**/
EFI_STATUS
EFIAPI
FileHandleDelete (
IN EFI_FILE_HANDLE FileHandle
);
/**
Set the current position in a file.
This function sets the current file position for the handle to the position
supplied. With the exception of seeking to position 0xFFFFFFFFFFFFFFFF, only
absolute positioning is supported, and seeking past the end of the file is
allowed (a subsequent write would grow the file). Seeking to position
0xFFFFFFFFFFFFFFFF causes the current position to be set to the end of the file.
If FileHandle is a directory, the only position that may be set is zero. This
has the effect of starting the read process of the directory entries over.
@param FileHandle The file handle on which the position is being set
@param Position Byte position from begining of file
@retval EFI_SUCCESS Operation completed sucessfully.
@retval EFI_UNSUPPORTED the seek request for non-zero is not valid on
directories.
@retval INVALID_PARAMETER One of the parameters has an invalid value.
**/
EFI_STATUS
EFIAPI
FileHandleSetPosition (
IN EFI_FILE_HANDLE FileHandle,
IN UINT64 Position
);
/**
Gets a file's current position
This function retrieves the current file position for the file handle. For
directories, the current file position has no meaning outside of the file
system driver and as such the operation is not supported. An error is returned
if FileHandle is a directory.
@param FileHandle The open file handle on which to get the position.
@param Position Byte position from begining of file.
@retval EFI_SUCCESS the operation completed sucessfully.
@retval INVALID_PARAMETER One of the parameters has an invalid value.
@retval EFI_UNSUPPORTED the request is not valid on directories.
**/
EFI_STATUS
EFIAPI
FileHandleGetPosition (
IN EFI_FILE_HANDLE FileHandle,
OUT UINT64 *Position
);
/**
Flushes data on a file
This function flushes all modified data associated with a file to a device.
@param FileHandle The file handle on which to flush data
@retval EFI_SUCCESS The data was flushed.
@retval EFI_NO_MEDIA The device has no media.
@retval EFI_DEVICE_ERROR The device reported an error.
@retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
@retval EFI_WRITE_PROTECTED The file or medium is write protected.
@retval EFI_ACCESS_DENIED The file was opened for read only.
**/
EFI_STATUS
EFIAPI
FileHandleFlush (
IN EFI_FILE_HANDLE FileHandle
);
/**
function to determine if a given handle is a directory handle
if DirHandle is NULL then ASSERT()
open the file information on the DirHandle and verify that the Attribute
includes EFI_FILE_DIRECTORY bit set.
@param DirHandle Handle to open file
@retval EFI_SUCCESS DirHandle is a directory
@retval EFI_INVALID_PARAMETER DirHandle did not have EFI_FILE_INFO available
@retval EFI_NOT_FOUND DirHandle is not a directory
**/
EFI_STATUS
EFIAPI
FileHandleIsDirectory (
IN EFI_FILE_HANDLE DirHandle
);
/**
Retrieves the first file from a directory
This function opens a directory and gets the first file's info in the
directory. Caller can use FileHandleFindNextFile() to get other files. When
complete the caller is responsible for calling FreePool() on *Buffer.
@param DirHandle The file handle of the directory to search
@param Buffer Pointer to pointer to buffer for file's information
@retval EFI_SUCCESS Found the first file.
@retval EFI_NOT_FOUND Cannot find the directory.
@retval EFI_NO_MEDIA The device has no media.
@retval EFI_DEVICE_ERROR The device reported an error.
@retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
@return Others status of FileHandleGetInfo, FileHandleSetPosition,
or FileHandleRead
**/
EFI_STATUS
EFIAPI
FileHandleFindFirstFile (
IN EFI_FILE_HANDLE DirHandle,
OUT EFI_FILE_INFO **Buffer
);
/**
Retrieves the next file in a directory.
To use this function, caller must call the FileHandleFindFirstFile() to get the
first file, and then use this function get other files. This function can be
called for several times to get each file's information in the directory. If
the call of FileHandleFindNextFile() got the last file in the directory, the next
call of this function has no file to get. *NoFile will be set to TRUE and the
Buffer memory will be automatically freed.
@param DirHandle the file handle of the directory
@param Buffer pointer to buffer for file's information
@param NoFile pointer to boolean when last file is found
@retval EFI_SUCCESS Found the next file, or reached last file
@retval EFI_NO_MEDIA The device has no media.
@retval EFI_DEVICE_ERROR The device reported an error.
@retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
**/
EFI_STATUS
EFIAPI
FileHandleFindNextFile(
IN EFI_FILE_HANDLE DirHandle,
OUT EFI_FILE_INFO *Buffer,
OUT BOOLEAN *NoFile
);
/**
Retrieve the size of a file.
if FileHandle is NULL then ASSERT()
if Size is NULL then ASSERT()
This function extracts the file size info from the FileHandle's EFI_FILE_INFO
data.
@param FileHandle file handle from which size is retrieved
@param Size pointer to size
@retval EFI_SUCCESS operation was completed sucessfully
@retval EFI_DEVICE_ERROR cannot access the file
**/
EFI_STATUS
EFIAPI
FileHandleGetSize (
IN EFI_FILE_HANDLE FileHandle,
OUT UINT64 *Size
);
/**
Function to get a full filename given a EFI_FILE_HANDLE somewhere lower on the
directory 'stack'.
if Handle is NULL, return EFI_INVALID_PARAMETER
@param[in] Handle Handle to the Directory or File to create path to.
@param[out] FullFileName pointer to pointer to generated full file name. It
is the responsibility of the caller to free this memory
with a call to FreePool().
@retval EFI_SUCCESS the operation was sucessful and the FullFileName is valid.
@retval EFI_INVALID_PARAMETER Handle was NULL.
@retval EFI_INVALID_PARAMETER FullFileName was NULL.
@retval EFI_OUT_OF_MEMORY a memory allocation failed.
**/
EFI_STATUS
EFIAPI
FileHandleGetFileName (
IN CONST EFI_FILE_HANDLE Handle,
OUT CHAR16 **FullFileName
);
/**
Function to read a single line (up to but not including the \n) from a file.
@param[in] Handle FileHandle to read from
@param[in,out] Buffer pointer to buffer to read into
@param[in,out] Size pointer to number of bytes in buffer
@param[in[ Truncate if TRUE then allows for truncation of the line to fit.
if FALSE will reset the position to the begining of the
line if the buffer is not large enough.
@retval EFI_SUCCESS the operation was sucessful. the line is stored in
Buffer. (Size was NOT updated)
@retval EFI_INVALID_PARAMETER Handle was NULL.
@retval EFI_INVALID_PARAMETER Buffer was NULL.
@retval EFI_INVALID_PARAMETER Size was NULL.
@retval EFI_BUFFER_TOO_SMALL Size was not enough space to store the line.
Size was updated to minimum space required.
@sa FileHandleRead
**/
EFI_STATUS
EFIAPI
FileHandleReadLine(
IN EFI_FILE_HANDLE Handle,
IN OUT VOID *Buffer,
IN OUT UINTN *Size,
IN BOOLEAN Truncate
);
/**
function to write a line of unicode text to a file.
if Handle is NULL, ASSERT.
if Buffer is NULL, do nothing. (return SUCCESS)
@param[in] Handle FileHandle to write to
@param[in] Buffer Buffer to write
@retval EFI_SUCCESS the data was written.
@retval other failure.
@sa FileHandleWrite
**/
EFI_STATUS
EFIAPI
FileHandleWriteLine(
IN EFI_FILE_HANDLE Handle,
IN CHAR16 *Buffer
);